Medical science has long sought ways to minimize the dangers and trauma inherent in invasive surgical procedures. To this end, surgical techniques and instruments have been developed which, among other things, reduce the size and number of the incisions required to perform various surgical procedures. These techniques and instruments have been remarkably successful. Procedures that only a few years ago would require multiple incisions several inches in length, are today being performed with just a few one-inch incisions.
During minimally evasive surgeries, surgical instruments such as trocars, cannulas, and optical medical devices, including endoscopes, cystoscopes, arthroscopes, laparoscopes, etc., are inserted through small incisions or portals in a patient's body or body cavity and manipulated to perform surgical procedures within the patient.
Minimally invasive surgical procedures are safer than open surgery and result in quicker patient recovery, shorter hospital stays, and lower health care costs. Accordingly, minimizing invasiveness continues to be of importance, and there is a continuing need for devices and methods that achieve this objective.
One significant barrier to further minimizing the invasiveness of surgery is the necessity of many surgical instruments to have fluid channels. These channels effectively add to the outer diameter of the instruments. For example, known endoscopic instruments provide inflow/outflow through an assembly of concentric sheaths that define channels for inflow and outflow of fluids to and from the operative or surgical site. The fluid may be an irrigating solution that helps maintain a clear view of the site for the physician. Certain known irrigating systems provide simultaneous and continuous inflow and outflow. These systems are known as “continuous flow” systems.
The known inflow and outflow endoscope systems introduce an irrigating fluid into the surgical site. For this purpose, the endoscope has an inflow channel defined by the inner surface of the inner sheath. The fluid passes through the channel and exits the distal end of the sheath to irrigate the operative site. Fluid at the surgical site may be withdrawn through an outflow channel defined by the outer surface of the inner sheath and the inner surface of a surrounding outer sheath. The outflow channel originates at the distal end (front end) of the instrument and transports fluid to an exit point at the proximal end of the outer sheath. The diameter of these systems require larger surgical portals.
Another barrier to minimally invasive surgery is the number of incisions or portals required by the surgeon in order to perform a surgical procedure. During many procedures, multiple portals are required to provide irrigation of the surgical site and removal of debris, view the surgical site with use of an endoscope, and facilitate the use of specialized surgical equipment to repair the injury or abnormality. Each incision creates additional risk of infection and extends recovery time.
A procedure where less invasive surgical techniques may be beneficial is arthroscopic surgery. Presently, arthroscopic surgical techniques use a standard three-portal (incision) technique. A first portal is made in the patient and then used to insert an arthroscope to view the surgical site. A second portal is created to insert a specialized surgical instrument to correct the injury or abnormality. Also, a third portal is usually made and then used to insert an inflow cannula to distend the joint. The inflow cannula is used to fill the joint with a sterile fluid to expand the joint and make room for the surgeon to see and work. After the procedure, the joint is washed out with a stream of fluid, the instruments are removed, and the portals are closed with stitches, staples, or Steri-strips. Having multiple portals, coupled with larger sized portals due to the size of the medical instruments, can be a source of postoperative pain and may inhibit postoperative recovery.
In arthroscopic surgery, as well as other surgical procedures, there remains a significant need for improved techniques that reduce the number of portals used by surgeons as well as reduce the size of the portals while providing continuous fluid inflow and outflow. The Applicant's improved inflow/outflow sheath reduces the diameter of the continuous flow system while eliminating the need for a third portal during arthroscopic surgery.